Locking-switch



E. 0. SESSIONS.

LOCKING swlTcH. APPLICATION FILED N0y.2, |917.-

; Patented Jan. 25, 1921.

2 SHEETS-SHEET 2 DSON 0. SESSIONS,A OF CHICAGO, ILLINOIS. i I f magma-SWITCH.

T 0 all whom t may conce/m.'

Be it known that I, EDsON Chicago, in the county of Cook and State of Illinois, have invented a certain new and luseful Improvement in Locking-Switches,

of which the following is aspecification.

My invention relates particularly to an improved eonstruction of locking switch of the lock-in lock-out type as used for example in connection with oil switches for controlling the cpnnection lof the main feeders to the mechanism of the oil switches, so that the oil switches may be disconnected from the main feeders when it is desirable to repair or inspect the oil switches. In connection with switches of this kind it has become necessary with the development of high tension alternating current systems to provide locking devices of the strongest and most positive kind so that the switches may be held in their closed position securely to guard against the heavy lateral thrusts eX- erted on the switch blades by an undue rush of current as for example when a total or partial short circuit occurs onv the devices supplied with current from the oil switches and furthermore the switches must be positively locked in open position when the oil switches are disconnected from thc main feeders so that the danger of the switches accidentally becoming closed while the oil switches are being inspected or repaired is eliminated. To secure the results now found t0 be necessary in practice I find it desirable to provide locking mechanism car ried by the switch blades which coperates with devices adjacent the clip contact of the switch as distinguished from the pivot clip, so that the locking of the switch in its closed position may be accomplished in the most effective manner, and I also provide devices associated with the support of the pivot contact for engaging the locking mechanism to hold the switch blades in their open position.

it will be understood that oil switches are usually mounted in inclosed casings with cut-out switch compartments below the oil switch compartments, thc dimensions of the cut-'out switch compartments in practice being no larger than is required to give aA Specication ofLetters Patent.

O. Sessions?. a citizen of the United States, residing at l Patented Jan. 25, 1921.

Application led November 2, 1917. Serial No. 199,971.

switchA to prevent passage through the air of current, as a result of the voltages employed. My present invention has for its purpose the production of a locking switch, which "while it secures the desired results already referred to, also maintains the highest possible striking distance between the terminals in the cut-out switch compartment, thus maintaining to the highest degree the striking distance between the terminals in the cut-out switch compartment.

My invention will best be understood by reference to the accompanying drawings showing preferred embodiments of my in- -vention, in which- Figure 1 shows in side elevation the por` tion of a cut-out switch compartment with my locking switch in place,

Fig. 2 Shows a detail View on an enlarged scale of the locking mechanism, a part of the casing being broken away to more clearly show said mechanism,

F ig. 3 is a view showing in front elevation the parts shown in Fig. 2,

Fig. 4 is a view similar to Fig. 1 showing a modified construction of switch, and

Fig. 5 is a view similar to Fig. 2 showing a modified construction of locking mechanism. f

Fig. 6 shows in a view similar to Fig. 5 a further modified construction of thmuocking mechanism.

Similarnumerals refer to similar parts throughout the several views.

As shown in Fig. 1 the walls of the'cutout switch compartment are indicated in dotted lines at 10 and in the botto'mwa'll an insulator 11 is mounted to support the terminal of the correspondingf'-mainfeeder while in the top wall 'of the compartment a second insulator 12 is mounted-to support the lower terminal of the corresponding oil switch mechanism. A conducting stud 13 projects below the insulator 12 and has rigidly secured to it a firstfsupport 14 while the insulator 11 has projecting from it a conducting stud 15 to which is rigidly se- Vcured a second support 16, these supports serving to support the cut-out switching mechanism.

The support 14 is in the form of a laterally extending bracket and has rigidly secured thereto the pivot clip 17 of the switch and to this pivot clip the switch blade or blades 18 are pivotally secured at 19. The

other endof the switch blade or blades engage, when they are in their closed position, the contact clip 20 rigidly supported by the support or bracket 16. The free end of the switch blades carry a casing 21 from which a first locking latch 22 extends to engage a catch 23 adjacent the clip contact 2O and a second locking latch 24 projects from said .casing to engage a catch 25 carried' by the contained in the casing 21 is best shown in Fig. 2, and as seen in that figure the latch 22 is pivotally mounted on a rod 28 carried by the casing and at its other end is provided with a slot for receiving a pin 29 carried by an operating member 30 which is pivotally supported upon a rod 31 carried by the casing 21. The member 30 extends beyond its pivot rod 31 and overlaps slots 32 formed through the opposite walls of the casing 21 to receive a suitable operating'tool not shown. A second operating member 33 is pivotally supported in the casing upon a rod 34 carried by the casing and this operating member in the form of a bell crank lever the short end of which -is provided with a slot for engaging a pin 35 carried by the member 30. The longer end of the bell crank lever extends over the slots 32. A helical spring 36 is mounted between the operating members 30 and 33 and secured at its ends-t0 pins carried.

by the said operating members as a result of which said operating members are normally held together against an abutment 37 extending into the casing 21. As a result of the construction described when the operating tool is inserted `through lthe slots 32 between the operating members 30 and 33 a pull toward the right on the tool exerts a corresponding pressure on the lower end of the operating member 30 which rotates said operating member around to the left on its pivot rod 31 and the pin 29 rotates' the latch 22 around to the right on its pivot rod 28 thus releasing the latch from engagement with the catch 23. On the other hand if the operating tool is moved to the left for the position of the parts shown in Fig. 2 a corresponding pressure is exerted on the operating member 33, which rotates the operating member 33 around to the right on its pivot rod 34 as a result of which the engagement between the operating member and the pin 35 rotates the operating member 30 around to the left on blades throughout the entire length of said its pivot rod 31, which in the manner describedmoves the latch 22 to its releasing position.

The latch 24 is pivotally supported in the casing 21 on ra rod 38 carried by the casing and is provided with an extending portion having a slot engaging a pin 39 carried by the operating member 30, the relation of the parts being such that rotation of the operating member 3() around t0 the left on its pivot rod rotates the latch 24 around to the right on its pivot rod, thus moving the latch 24 to its releasing position.

It will be noted that the slots 32 extending through the casing 21 are curved toward the pivot 19 of the switch blades adjacent the operating member 33. The purpose of this will best be understood by reference to Fig. 1. As shown in that figure 1t will be observed that the insulator 12 is at some distance from the front right hand side of the casing containlng the switching mechanism, which is necessary in oil switch construction, as a result of which the lower right hand corner of the compartment containing the oil switch mechanism is in a position making it impossible to place the operating tool in a vertical position -when it is inserted in the slots 32 to move the switch from its open position to its closed position. In practice-95 it is seldom possible to arrange the parts of the cut-out switch so that the operating tool can assume a position more nearly vertical than 45 degrees with a horizontal plane and with the slots 32 extending vertically, a longitudinal thrust exerted on the operatlng tool in the position referred to could not be communicated effectively to the operating member 33 to release the latch 24 from the catch 25. By giving the slots 32 a curved formation as described and correspondingly shaping the end of the operating member 33 the thrust exerted on the oper-ating tool is effectively communicated to the operating member 33 and the locking mechanism is easily operated to release the latch 24 from the corresponding catch. It will also be observed that if the slots 32"were' given a 45 degree inclination to the axis of the switch slots, when the operating tool is inserted through the slots to open the switch from its closed position the thrust exerted upon the operating tool would vwith difliculty operate the operating mechanism on account ot' the inclination of the operating tool to the slots, as a result of which the portions of the slots adjacent the operating'member 30 are preferably formed to extend at substantially right angles to the longitudinal axis of the switch 1 blades.

v From the above description it will appear that by mounting the locking mechanism in a casing separate from the switch blades the locking mechanism may be made as rigid the switch blades.

and strong as may be necessary to ymeet any practical requirements and furthermore since the locking mechanism with the exception of the projecting latches 22 and 24 is entirely inclosed within the casing 21, the parts are ei'l'ectively protected from dirt and foreign matter getting into the locking mechanism and the mechanism isfurther protected from injury due to improper handling of the operatlng tool or tampering.

In Fig. 4 a lconstruction is illustrated lwhich may be used where the distance between the terminals is somewhat greater than that assumed in Fig. 1 `or the voltages employed are suiiiciently less than those used in Fig. 1, so that the casing of the locking mechanism may be mounted on the ends of In this construction the support or bracket 14a is similar to `the bracket 14 shown in Fig. 1 and similarly supports the switch blades 18a. The second support 16a in this construction extends upwardly andto the left at an angle to support the contact clip 20El at a suiiicient distance from the lower terminal stud 15, so

.that the entire casing 21a for the locking mechanismis located below and to the right of the contact clip 20a, the casing being connected. to the extreme ends of the, switch blades 18a. The locking mechanism may be the same as described above in connection with Figs. 1 and 2.

' In the modified form of locking mechanism shown in Fig. 5 the switch blades 18b carry at or near their free ends a casing 21b in which there is pivotally supportedl a double latch 40 on a rod 41 carried by the I casing. The portion 40a ofthe latch is similar to the latch 22 above described and serves the same purpose while the portion 40b is similar to the latch 24 described above and .performs the same purpose as the latch 24.v

The double latch 40 is providedvwith an offset portion having a slot engaging a pin 42 carried by a first operating member 43 which is pivotally mounted on a'rod 44 carried by the casing 21". The operating member 43 is extended beyond its pivot rod to overlap the slots 32a formed through the opposite walls of the casing 21b to receive an operating tool and a second operating member 45 is' pivotally mounted in the casing 21b on a rod 46 carried by the casing. and this operat ing member is provided 'with an extending portion having a slot .engaging a pin 47 carried by the operating-member 43. v The operating mem er 45-overlaps the slots. 32 at their ends Iop o site the operating member 43. A helica spring/48 1s connected at its ends to the operating menbers43`and 45 to normally hold thenilagainst an abutment projecting into the casing21". The slots 32 and the relation of theo eratin members 43 and 45 thereto are-simi ar to t e slots 32 and the relation lof the operating members '30 and 33 thereto and the locking mechanism shown in Fig. 5 is operated in the same manner as that described above for the locking mechanism shown in Fig. 2. The locking mechanism shown in Fig. 5 has the advantage o fewerl parts than that shown in Fig. 2 and may be employed where there is opportunity to place the catches so that they maglbe engaged by the double latch. ile I have shown my invention in the particular embodiment above described it will be understood that I do no limit myself to these exact constructions as I may employ equivalents thereof known to the art at the time of the filing of this application without departing from thescope of the appended claims.

The modified construction shown in Fig. 6 is similar to that shown in Fig. 5 as to the general construction and disposition of the locking latch of the operating members. In

this construction the casing 21C carried in Fig. 5 and similarly supported in the casing 21e is provided with a lug 51a engaging Y' a corresponding notch in the side of the operating member 50, as a result of which the operation of either operating member'by an operating tool operates the double latch 49 to move it to its releasing osition in substantially the manner described in connection with Fig. 5. In the construction shown in Fig. 6 a helical spring 52 is dis-- posed with 'one end in engagement with a pin carried by the latch 49 and the other end secured to the casing 21e in a manner to hold the latch 49 in its locking position.

What I claimis:

1., A locking switch of the lock-in lockout type, the combination of a first support, a pivot clip carried by said support, a'switch blade pivoted to said pivot clip, locking mechanism carried bysaid switch blade, a second support, a contact clip carried by said second support for engaging said switch blade in its closed position, a catch carried by said second support engaging said locking mechanism in the closed-positionA of said switch, and a catch carried by said first supmechanism carried by said switcliblade, aY

second support, a contact clip carried by said second support for engaging said switch blade in its closed position, a catch carried by said second support engaging mechanism in the open position of sai switch, and a casing carried bysaid switch blade for containing said locking lnechalnism, said casing having slots through its.

opposite walls Jfor receiving an operating tool, said slots having one nclinationto said switch blade at one end and a. different inclination to said switch blade at the other end of said. slots. l

3. In a locking switch ofthe lock-in lockout type, the combination of a first support, a pivot clip carried by said support, a switch blade 'pivoted to said pivot clip, locking mechanism carried by said switch blade, a second support, a contact clip carried by said secondsupport for engaging said switch blade in its closed position, a catch carried by said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said first support engaging said locking mechanism in the open position of said switch, and a casing carried by said switch blade-or--containing said locking mechanism, said casing having slots through its opposite walls for receiving an operating tool, said slots having one inclination to said switch blade at one end and a different inclination to said switch blade at the other end of. said slots, said locking mechanism comprising y latching mechanism for engaging said catches, and two operating members articulating with said latching mechanism, one of said operating members overlapping said slots at' one end thereof and the other of said operating members overlapping said slots at the other end thereof, whereby motion of either operating member away from the middle\,por tion of said slots releases said latching mechanism.

4. In a locking switch of the lock-in lockout type, the combination of a first support, a pivot clip carried by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by said switch blade,

va second support, a contact clip carried by said second support for engaging said switch blade in its closed position, a catch carried by said second support enga-ging said locking mechanism in the closed position of said switch, and a catch carried by said first support engaging said locking mechanism in the open position of said switch, and a casing carried by said switch blade for containing said locking mechanism, said casing having slots through its opposite walls for receiving an operating tool, said slots having one inclination to said switch blade at one end and a difierent inclination to said switch blade at the other end of said slots, said locking mechanism comp-rising latching mechanism for engaging sa-idcatches, and two operating members aiticulatino with said latching mechanism, one of sait operating members overlapping said slots at one end thereof and the other of lsaid operating members overlapping said slots at the other end thereof, whereby motion of either operating member away from the middle position of said slots releases said latching mechanism, a spring secured said switch blade in its closed position, a

catch carried by said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said first sup ort engaging said locking mechanism in tie open position of said switch, and a casing carried by said switch blade for containing said locking mechanism, said 'casingY having slots through its opposite walls for receiving an operating tool. said slots having one inclination to said switch blade at one end and a different inclination to said switch blade at the other end of said slots, and a bracket carried by said switch blade between its pivot clip and its contact clip for supporting said casing.

6. In a locking switch of the lock-in lock-y out type, the combination of a first support, a pivot clip carried by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by said switch blade, a second support, a contact clip carried by said second support for engaging said switch blade in @its closed position, a catch carried by said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said first support engaging said locking-mechanism in the open position of said switch, and a casing carried b said switch blade for containing said locking mechanism, said casing having slots through its opposite walls for receiving an operating tool, said slots having one inclination to said switch blade at one end and a different inclination to said switch blade at the other end of said slots, said locking mechanism comprising latching mechanism kfor engaging said catches, and

two operating members articulating with said latching mechanism, one of said operating members overlapping said slots at one end thereof and the other of said operating members overlapping said slots at the other end thereof, whereby motion of either operating member away from the middle portion of said slots releases said latching mechanism, and a bracket carried by said switch blade between its pivot clip and its contact clip for supporting said casing.

7. 1n al locking switch of the lock-in lockout type, the combination of a first support, a pivot clip carried by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by said switch blade, a second support, a contact clip carried by said second support for engaging said switch blade in its closed position, a catch carried by saidV second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said first support engaging said locking mechanism in the open position of said switch, and a casing carried by said switch blade for containing said locking mechanism, said casing having slots through its opposite walls for receiving an operating tool, said slots having one inclination to said switch blade at one end and a different inclination to said switch blade at the other end of said slots, said locking mechanism comprising latching'mechanism for engaging said catches, and two operating 1` members articulating with said latching mechanism, one of said operating members overlapping said slots at one end thereof and the other of said operating members overlapping said slots at the other end thereof, whereby motion of either operating member away from the middle position of said slots releases said latching mechanism, a spring secured to said operating members and tending to hold them together, and an abutment carried by said casing for holding lsaid operating members a sufficient distance apart to permit the insertion of an operating tool, and a bracket carried by said switch blade between its pivot clip and its contact clip for Supporting said casing.

8. In a locking switch of the lock-in lockout type, the combination of a first support, a pivot clip carried by said support, a switch blade pivoted' to said pivot clip, locking mechanism carried by said switch blade, a

second' support, a contact clip carried by said second support for engaging said switch blade in its closed position, a catch carried by said second support engaging said locliing mechanism in the closed position of said switch, and a catch carried by said first support engaging said locking mechanism in the open position of said switch, anda casing carried by said switch bla'de for containing said Alocking mechanism, said ,casing having slots through its opposite walls for receiving an operating tool` said slots having one 1nclination to said switch blade at one end and for en raging said catches and two ivoted operating members articulating with each other. and with said latching mechanism, one of said operating members overlapping said slots at one end thereof and the other of said operating members overlapping said slots at the otherl end thereof, whereby motion of either operating member away from the middle portion of said slots'releases said latching mechanism.

9. In a locking switch of the lock-in lockout type, the combination of afrst support, a pivot clip carried by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by said switch blade, a second support, a contact clip carried by said second support for engaging said switch blade in its closed position, a catch carried by said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said first support engaging said locking mechanis'mfin the open position of said switch, and a casing carried by said switch blade for containing said locking mechanism, said casing having slots through its opposite walls for receiving an operating tool, said slots having one inclination to said switch blade at one end and a v`different inclination to said switch blade at the other end thereof, whereby motion of either operating member away from the middle portion of said slots releases said latching mechanism, a spring secured to said opf erating members and tending to hold them together, and an abutment carried by said casing for holding said operating members a sufiicient distance apart to permit the insertion of an operating tool.

10.*In a locking switch of the lock-in lockout type, the combination of a first support, a pivot clip carried by said support, a switch blade pivoted to .said pivot clip, locking mechanism carried by said switch' blade, a second support, a contact clip carried by said second support lfor engaging said switch blade in its closed position, a catch carried by said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said first supslots through its opposite walls for receivingl ing.

an operating tool, said slots having one inclination to said switch blade at one end and a different inclination to said switch blade at the other end of said slots, said locking mechanism comprising latching mechanism f for engaging said catches and two pivoted operating members articulating with -each other and with said latching mechanism, one

of said operating members overlapping said 11. In a locking switch of the lock-in lockout type, the combination of a first support,

f a' pivot clip carried by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by said switch blade, a

second support, a contact clip carried by said second support for engaging said switch blade in its closed position, a catch carried by said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said first support engaging said lookin mechanism in the open position of said switch, and a casing carried by said switch blade for containing said locking mechanism, said casing having slots through its opposite walls for receiving an operating tool, said slots having one inclination to said switch blade at, one end and a different inclination to said switch blade at the other end of said slots, said locking mechanism comprising latching mechanism for engaging said catches and ltwo pivoted operating members articulating with each other and with said latching mechanism, one

of said operating members overlapping said slots at one end thereof and the other of said operating members overlapping said slots at the other end thereof, whereby motion of either operating member away from the middle portion of said slots releases said latching mechanism, a spring secured to said operating members and tending to hold them together, and an abutment carried by said casing for holding said operating members a sufficient distance apart to permit the insertion of an operating-tool, and a bracket carried by said switch blade between its pivot' clip and its` contact clip for supporting said casing.

12.'In a-locking switch of the lock-iii lockout type, the combination of a first support, a pivot clip carried by said support, a switch blade pivoted to said ipivot clip, locking mechanism carried by said switch blade, a second support, a contact clip carried by said second support-for engaging said switch .blade in its closed position, a catch carried 'one end and a different inclination to said switch blade at the other end of said slots,

said locking mechanism comprising twopivoted latches, one for holding said switch in its closed lposition and the other for holding said switch in its open position, and two operating members articulating with said latches, one of said operating members overlapping said slots at one end thereof and the other of said operating members overlaplping said slots at the other end thereof,

whereby motion of either operating member away from'the middle portion of said slots releases said latching mechanism.

13.. In a locking switch of the lock-in lockout type, the combination of a first support, a pivot clip carried by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by said switch blade, a

second support, a contactclip carried by Said second support for engaging said switch blade'in its closed position, a catch carried by Said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said iirst'support engaging said locking mechanism in the open position of said switch, anda casing carried by said switch blade for containing said locking mechanism, said casing having slots through its opposite walls for -receiving an operating tool, said slots having one inclination to said switch blade at one end and a diiferent inclination to said switch blade at the other end of said slots, said locking mechanism comprising twopivoted latches, one foryholding said switch in its closed position and the other for holding said. switch in its open position, and two operatlng members articulating with said latches, one of said operating members overlapping said slots at one end thereof and the other of said operating members overlapping said slots at the other end thereof, whereby motion of either operating member away from the middle portion of said slots releases said latching mechanism, a spring secured to said operating members and tending to hold them together, and an ab-utment carried by said casing for holding said operating members a suicient distance apart to permit the insertion of an operating tool.

14. 'in a locking switch of the lock-in lockout type, the combination of a first support, a pivot clip carried by said support, a switch blade pivoted to said pivot clip, a

locking mechanism carried by said switch blade, a second support, a contact clip carriedpby said second support for engaging said switch blade in its closed position, a catch carried byl said second support engaging said locking mechanism in the closedposition of said switch,-and a catch carried by said first support engagingA said locking ,mechanism 1n the open position of said ing saidsswitch 1n its closed position and the other for holding saidswitch in its open position and two pivoted operating members articulating with eachother and with said latches, one of said operating members overlapping said slots at one end thereof andl the other of said operating members overlap,- ping said slots at the other end thereof,

whereby motion of either operating member away from the middle portion of said slots releases said latching mechanism.

'15. In a locking switch of the lock-in lockout type, the combination of a first support, a pivot clip carried by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by said switch blade, a second support, a contact clip carried by said second support for engaging said switch blade in its closed position, 'a catch carried by said second sup ort engaging said locking mechanism in t e closed position of said switch, and a catch carried by said first support engaging said locking mechanism in the open position of' said switch, and a caslng carried by said switch blade for containing said locking mechanism, said casing having slots through its opposite walls for receiving an operating tool, said slots having one inclination to said switch blade at one end and a different inclination to said switch blade at the other end of said slots, said locking mechanism comprising two pivoted latches, one for holdingsaid switch in its closed position and the other for holding said switch in its open position, and two pivoted operating members articulating with each other and with said latches, one of said operating members overlapping said slots at one end thereof and the other of said operating members overlapping said slots at the other end thereof, whereby motion of either operating member away from the middle vportion of' said slots releases said latching mechanism, a spring secured to said operating members and tending to hold them together, and an abutment carried by said casing for holding said operating members a sufficient distance apart to permit the insertion of an operating tool.

16. In a locking switch of the lock-in lockout type, the .combination of a first support, a pivot clip carried by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by said switch blade, a second support, a contact clip carried by said second support for engaging said switch blade in its ,closed position, a catch carried by said second supportengaging said locking mechanism in the closed position of said switch, and a catch carried by said first support engaging said locking mechanism in the openposition of said switch, and a casing carried by said switch blade for containing saidlocking mechanism, said casing having slots through its opposite walls for receiving an operating too-l, said slots having one inclination to said switch blade at one end and a different inclination to said switch blade at theother end of said slots, said locking mechanism comprising two pivotedlatches, one for holding said switch in its closed position and the other for holding said switch in its open position, and two operating members articulating with said latches,`one of said operating members overlapping said slots at one end lthereof and'the other of said operating members overlapping said slots at the other end thereof, whereby motion of either operating member away from the middle poition of said slots releases said lout type, the combination of a first support,

a pivot clip carried by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by saidy switch blade, a second support, a contact clip carried by said second' support for engaging said switch blade in its closed'position, a catch carried by said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by .said first support engaging said locking mechanism in. the open position of said switch, and a casing carried by said switch blade for containing said locking mechanism, said lcasing having slots through' its opposite walls for receiving an operating tool, said slots having one inclination to said switch blade at one end and a different inclination to said switch blade at the other end of said slots, said locking mechanism comprising two pivoted latches, one for holding said switch in its closed position and the other for holding said switch in its open position, and two operating members articulating with said latches, one of said operating members overlapping said slots at one end thereof and theother of said operating members overlapping said slots at the other end thereof, whereby motion of either ing one inclination to said switch blade at operating member away from the middle .Mone end and a different inclination to said portion of said slots releases said latching mechanism, a spring secured to said operating members and tending to ,hold them together, and an abutment carried by said casinv for holding said "operating members a suicient distance apart to permit the insertion of an operating tool, and a bracket carried by said switch blade between its pivot clip and its contact clip for supporting said casing.

18. In a locking switch ofthe lock-in lock-out type, the combination of a first support, a pivot clip carried `by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by said switch blade, a second support, a contact clip carried by said second support for en: gaging said switch blade in its closed position, a catch carried by said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said first support engaging said locking mechanism in the open position of said switch, and a lcasing carried by said switch blade for containing said locking mechanism, said casing having slots through its opposite walls for receiving an operating tool, said slots having one inclination to said switch blade at one end and a diiferent inclination to said switch blade at the other end of said slots, said locking mechanism comprising two pivoted latches, one for holding said switch in its closed position and the other for holding said switch in its open position, and two pivoted operating members articulating with each other and with said latches, one of Said operating members overlapping said slots at one end thereof and the other of said operating members overlapping said slots at the other end thereof, whereby motion of either operating member away from the'middle portion of said slots releases said latching mechanism, and a bracket carried by said switch blade between its pivot clip and its contact clip for supporting said casing.

19. In a locking switch of the lock-in lock-out type, the combination of a first support, a pivot clip carried by said support, a switch blade pivoted to said pivot clip, locking mechanism carried by said switch blade, a second support, a contact clip carried by said second support for engaging said switch blade in its closed position, a catch carried by said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said first support engaging said locking mechanism in the open position of said switch, and a casing carried by said switch blade for containing said locking mechanism, said casing having slots. through its opposite walls for receiving an operating tool, said slots havswitch blade at the other end of said slots, said locking mechanism comprising two pivoted. latches, one for holding said switch in its closed position and the other for holding said switch in its open position, and two operating members articulating with each'other and with said latches, one of said operating members overlapping said slots at one end thereof and the other of said operating members overlapping said slots at the other end thereof, whereby motion of either operating member away from the middle portion of said slots releases said latching mechanism, a spring secured to said operating members and tending to hold them together, and an abutment carried by said casing for holding said operating members a suicient distance apart to permit the insertion of an operating tool, and a bracket carried by said switch blade between its pivot clip and its contact clip for supporting said casing.

20. In a locking switch of the lock-in lock-out type, the combination of a first support, a pivot clip carried b said support, a switch blade pivoted to sai pivot clip, locking mechanism carried by said switch blade, a second support, a contact clip carried by said second support for engaging said switch blade in its closed position, a catch carried by said second support engaging said locking mechanism in the closed position of said switch, and a catch carried by said first support engaging said locking-mechanism in the open position of said switch` and a. casing mechanism in the closed position of said;

switch, and a catch carried by said first support engaging said locking mechanism in the open position of said switch. and a casing carried by said switch blade for containing said locking mechanism, said casing having slots through its opposite walls for receiving an operating tool. and a bracket carried by said switch blade between its pivot clip and its contact-clip for supporting said casing.

` In Witness whereof, I hereunto subscribe my name this 25th day of October, A. D.

EDSUN O. SESSIONS. 

